This read-only object, measured in MHz, reports the lowest frequency edge of the duplexer's low passband, the frequency below which the duplexer begins to attenuate signals rather than pass them cleanly. Knowing this boundary lets an admin verify that the radio's configured operating frequency actually falls inside the hardware's passable range for that duplexer. For instance, if a technician is planning to retune a link to a frequency near the low end of the band, checking this OID first confirms whether that frequency still lies within the duplexer's low passband.